wip: (wasm-smith): allow specifying the set of valid imports

crates/wasm-smith/src/ast.rs

@@ -0,0 +1,94 @@
+/// TODO
+#[derive(Debug)]
+pub struct Import {
+    /// TODO
+    pub module: String,
+    /// TODO
+    pub name: Option<String>,
+    /// TODO
+    pub desc: EntityDesc,
+}
+
+/// TODO
+#[non_exhaustive]
+#[derive(Debug)]
+pub enum EntityDesc {
+    /// TODO
+    Func(FuncType),
+    /// TODO
+    Global(GlobalType),
+    /// TODO
+    Table(TableType),
+    /// TODO
+    Memory(MemoryType),
+    /// TODO
+    Instance(InstanceType),
+}
+
+/// A function type.
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub struct FuncType {
+    /// Types of parameters of the function.
+    pub params: Vec<ValType>,
+    /// Types of results of the function.
+    pub results: Vec<ValType>,
+}
+
+/// TODO
+#[derive(Clone, Debug, PartialEq)]
+pub struct GlobalType {
+    /// TODO
+    pub val_type: ValType,
+    /// TODO
+    pub mutable: bool,
+}
+
+/// Primitive WASM type.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[non_exhaustive]
+pub enum ValType {
+    /// Signed 32-bit integer.
+    I32,
+    /// Signed 64-bit integer.
+    I64,
+    /// 32-bit floating point number.
+    F32,
+    /// 64-bit floating point number.
+    F64,
+    /// TODO:
+    V128,
+    /// TODO:
+    FuncRef,
+    /// TODO:
+    ExternRef,
+}
+
+/// TODO:
+#[derive(Clone, Debug)]
+pub struct MemoryType {
+    /// TODO:
+    pub limits: Limits,
+}
+
+/// TODO:
+#[derive(Clone, Debug)]
+pub struct TableType {
+    /// TODO:
+    pub limits: Limits,
+    /// TODO:
+    pub elem_ty: ValType,
+}
+
+/// TODO:
+#[derive(Clone, Debug)]
+pub struct Limits {
+    /// TODO:
+    pub min: u32,
+    /// TODO:
+    pub max: Option<u32>,
+}
+
+#[derive(Debug)]
+pub struct InstanceType {
+    pub exports: indexmap::IndexMap<String, EntityDesc>,
+}

crates/wasm-smith/src/config.rs

@@ -2,6 +2,8 @@
 
 use arbitrary::{Arbitrary, Result, Unstructured};
 
+use crate::Import;
+
 /// Configuration for a generated module.
 ///
 /// Don't care to configure your generated modules? Just use
@@ -48,6 +50,16 @@ pub trait Config: Clone {
         100
     }
 
+    /// Return the available set of imports.
+    ///
+    /// By default, returns `None` which means that any arbitrary import can be generated.
+    ///
+    /// To only allow imports from a specific set, override this to return a vec of
+    /// each available import.
+    fn available_imports(&self) -> Option<Vec<Import>> {
+        None
+    }
+
     /// The minimum number of functions to generate. Defaults to 0.  This
     /// includes imported functions.
     fn min_funcs(&self) -> usize {